The use of gyros and accelerometers to provide inertial guidance of over-the-horizon and other deliverables, such as ballistic missiles, is a technique well-known to those skilled in the art. Typically, the gyros provide attitude information and the accelerometers provide, via multiple integration, position information. The attitude and position information enables on-board autopilots to calculate the position and velocity of the deliverables with respect to inertial space.
In order to secure the degree of precision-performance often required in ballistic missile and other applications, it has been necessary heretofore to gimbal and to float the gyro elements in such a way that they are neutrally buoyant with respect to the body of the deliverable and at rest with respect to inertial space. The complexity of the mechanisms deployed both to gimbal and to float the gyro elements not only have rendered them expensive to manufacture, but also has rendered them difficult to maintain and to fix. While ways have been sought to replace the expensive floating and gimballed gyro-based inertial guidance systems with strap-down gyros, because such strap-down gyro elements would themselves be subjected to large forces due to the accelerations of the deliverable to which they are strapped, which forces would produce position and other errors in gyro output, it has heretofore not been thought possible to provide high-permanence inertial guidance with comparatively low-cost and easy to maintain strap-down gyro elements.